In Oct 28 2011, while I was working to recover a production reporting oracle database sync SQL facility provide by MES vendor Camstar, I meet the ORA-02049 error, Such error is never observed, but after kill session relative with sync SQL in production transaction database, the whole sync SQL facility return to normal.

So except the reason suggested by the Burleson Consulting, the root cause in my case can be the reporting server suddenly down and in it’s 2 phase commit, there is exist a lock in transaction database but rebooted reporting server’s oracle now can not known it. so after kill that pending session, the ORA-02049 error disappeared.

Suddenly UNIX server reboot/memory dump is still possible, so I record here and hoping its useful for you.